The hydraulic hybrid UPS truck Credit: Michael Stebbins
When a United Parcel Service representative told me he was going to have to "confiscate the hat," I chuckled. My $0.25, garage sale UPS hat was a security liability—apparently a UPS uniform grants you the ability to freely walk into most government buildings. I wanted to wear the hat during my ride in the first hydraulic hybrid delivery vehicle: fittingly, a UPS truck, unveiled Wed., June 21st in Washington, D.C., by the Environmental Protection Agency.
There has been a lot of chatter about hybrid cars, hydrogen-powered cars and even solar-powered cars coming to market in order to help us kick our "addiction to oil." But few designs for viable alternatives to large gas guzzling vehicles, like delivery and garbage trucks, have come out of the engineering box. This new UPS truck, designed and built by engineers working for the EPA's Clean Automotive Technology program in Ann Arbor, Michigan, runs on a combination of combustion engine and hydraulic pumps.
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The concept is surprisingly simple: When you step on the gas, the diesel engine drives hydraulic pumps that power the wheels and charge hydraulic storage tanks. When you let up on the gas, the engine shuts off completely and the hydraulic chambers engage to power the truck. There is no direct drive shaft from the engine to the wheels. When you brake, the forward momentum of the vehicle is converted to energy that is stored in the high-pressure hydraulic tanks, an efficiency concept reminiscent of hybrid electric cars that charge the car's battery with the energy created by braking. That process, in hybrids, can recover about 20% of the car's moving energy; in the hydraulic truck, an astounding 70% of the energy is recovered. For the stop/start use common to most UPS trucks, that translates to a 60% to 70% increase in fuel efficiency.
The first two prototypes for the vehicle will hit the road this year, signaling a huge victory for engineers in the EPA's Clean Automotive Technology program.
"Money is so tight that to build these highly regarded prototypes the engineers often used parts from junkyards."
At the unveiling at EPA headquarters, agency administrator Stephen Johnson, flanked by three Congressmen—Rep. Mark Souder (R-IN), Rep. Rahm Emmanuel (R-IL), and Rep. Stephanie Tubbs Jones (D-OH)—went out of his way to mention the President's commitment to developing new technology to relieve the US of its burdensome oil imports. The development of the hydraulic truck was an example of that dedication, a point he made roughly eight times in his five-minute speech.
"The President knows that America is too reliant on foreign energy," Johnson said. "And the best way to jump off this treadmill of dependency is through innovative technology."
On the surface this seemed like a real shift in policy for the administration and just about every news story on the event echoed that point.
Layout of the hydraulic hybrid system Credit: Lois Platte
Perhaps the administrator was unaware that between 2002 and 2006, the President's annual budget requests and Congress had tag-teamed the Clean Automotive Technology program, slashing its budget in half to $10 million per year for the 35 engineers working to reinvent the engine. In his budget request for 2007—released just after his State of the Union address, in which he announced his Advanced Energy Initiative to decrease our oil imports from the Middle East as much as 75% by 2025—the President asked Congress to cut the budget for the program to a paltry $3.6 million.